I am with Albane - You have done every reasonable thing you could and you should no longer be held hostage. I understand verbal contracts but again, without the other party holding up their end of the contract, I would say that said contract is now null and void! If it would make you feel better, perhaps you could speak with an attorney - legal aid would be good - and they would probably say you are free from obligation. You might place an ad in a couple of newspapers, under legal notices, announcing your intent and then move on and sell your corsets.
Beautiful designs and wonderful workmanship. You should be rightfully be able to make a living from your work and no longer have to wait to move forward.
Wish you all the best - when you get up and running, please let us know how you are doing!